Generally, for preparing spectacle lenses, spectacle wearing parameters measured in a state in which a spectacle wearer is wearing a spectacle frame are required. As the spectacle wearing parameters, a corneal vertex distance, a frame forward-tilt angle, a fitting-point position, an interpupillary distance, a frame warp angle, etc. are known.
Measurement of the spectacle wearing parameters is performed by using a dedicated measuring device. Examples of the dedicated measuring device include a device configured to image the face of a subject in a spectacle-frame wearing state and compute and obtain various spectacle wearing parameters based on the face images, which are imaging results thereof (for example, see Patent Literature 1). Specifically, in the measuring device disclosed in Patent Literature 1, the imaging result of the face of the subject is displayed on a screen, a point serving as a reference for measurement (for example, a corneal vertex of the subject, a spectacle-frame front frame, or the like) is specified while a cursor mark or the like is utilized on the screen, and, then, the spectacle wearing parameters such as the corneal vertex distance and the frame forward-tilt angle are computed and obtained based on the position of the measurement reference point on the screen (for example, see the description of paragraphs “0033” to “0035” of Patent Literature 1).
Meanwhile, in order to change the relative positions between the eye position of a spectacle wearer and a spectacle lens, a deformation mechanism is sometimes provided for temples of the spectacle frame. In that case, the temple width is widened with respect to the spectacle frame (for example, see FIG. 1A and FIGS. 2 to 3 of Patent Literature 2).